问题
Does anyone know how to convert a UIImage to a Base64 string, and then reverse it?
I have the below code; the original image before encoding is good, but I only get a blank image after I encode and decode it.
NSData *imageData = UIImagePNGRepresentation(viewImage);
NSString *b64EncStr = [self encode: imageData];
NSString *base64String = [self encodeBase64:imageData];
回答1:
Swift
First we need to have image's NSData
//Use image name from bundle to create NSData
let image : UIImage = UIImage(named:"imageNameHere")!
//Now use image to create into NSData format
let imageData:NSData = UIImagePNGRepresentation(image)!
//OR next possibility
//Use image's path to create NSData
let url:NSURL = NSURL(string : "urlHere")!
//Now use image to create into NSData format
let imageData:NSData = NSData.init(contentsOfURL: url)!
Swift 2.0 > Encoding
let strBase64:String = imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)
Swift 2.0 > Decoding
let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)!
Swift 3.0 > Decoding
let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!
Encoding :
let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
print(strBase64)
Decoding :
let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions(rawValue: 0))!
let decodedimage:UIImage = UIImage(data: dataDecoded)!
print(decodedimage)
yourImageView.image = decodedimage
Swift 3.0
let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!
let decodedimage = UIImage(data: dataDecoded)
yourImageView.image = decodedimage
Objective-C
iOS7 > version
You can use NSData's base64EncodedStringWithOptions
Encoding :
- (NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}
Decoding :
- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
return [UIImage imageWithData:data];
}
iOS 6.1 and < version
First Option : Use this link to encode and decode image
Add Base64 class in your project.
Encoding :
NSData* data = UIImageJPEGRepresentation(yourImage, 1.0f);
NSString *strEncoded = [Base64 encode:data];
Decoding :
NSData* data = [Base64 decode:strEncoded ];;
image.image = [UIImage imageWithData:data];
Another Option: Use QSUtilities for encoding and decoding
回答2:
Swift 4.2 Extension method
extension UIImage {
func toBase64() -> String? {
guard let imageData = self.pngData() else { return nil }
return imageData.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
}
}
XCode 9.1 and Swift 4.0
//
// Convert UIImage to a base64 representation
//
class func convertImageToBase64(image: UIImage) -> String {
let imageData = UIImagePNGRepresentation(image)!
return imageData.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
}
//
// Convert a base64 representation to a UIImage
//
class func convertBase64ToImage(imageString: String) -> UIImage {
let imageData = Data(base64Encoded: imageString, options: Data.Base64DecodingOptions.ignoreUnknownCharacters)!
return UIImage(data: imageData)!
}
回答3:
SWIFT 3.0, XCODE 8.0
Replace String with your URL. and testImage is an outlet of ImageView
// Put Your Image URL
let url:NSURL = NSURL(string : "http://.jpg")!
// It Will turn Into Data
let imageData : NSData = NSData.init(contentsOf: url as URL)!
// Data Will Encode into Base64
let str64 = imageData.base64EncodedData(options: .lineLength64Characters)
// Now Base64 will Decode Here
let data: NSData = NSData(base64Encoded: str64 , options: .ignoreUnknownCharacters)!
// turn Decoded String into Data
let dataImage = UIImage(data: data as Data)
// pass the data image to image View.:)
testImage.image = dataImage
Hope It Helps Thanks.
回答4:
Swift iOS8
// prgm mark ----
// convert images into base64 and keep them into string
func convertImageToBase64(image: UIImage) -> String {
var imageData = UIImagePNGRepresentation(image)
let base64String = imageData.base64EncodedStringWithOptions(.allZeros)
return base64String
}// end convertImageToBase64
// prgm mark ----
// convert images into base64 and keep them into string
func convertBase64ToImage(base64String: String) -> UIImage {
let decodedData = NSData(base64EncodedString: base64String, options: NSDataBase64DecodingOptions(rawValue: 0) )
var decodedimage = UIImage(data: decodedData!)
return decodedimage!
}// end convertBase64ToImage
回答5:
Swift 5
Encoding
func ConvertImageToBase64String (img: UIImage) -> String {
return img.jpegData(compressionQuality: 1)?.base64EncodedString() ?? ""
}
Decoding
func ConvertBase64StringToImage (imageBase64String:String) -> UIImage {
let imageData = Data.init(base64Encoded: imageBase64String, options: .init(rawValue: 0))
let image = UIImage(data: imageData!)
return image!
}
Note: Tested in xcode 10.2
Swift 4
Encoding
func ConvertImageToBase64String (img: UIImage) -> String {
let imageData:NSData = UIImageJPEGRepresentation(img, 0.50)! as NSData //UIImagePNGRepresentation(img)
let imgString = imageData.base64EncodedString(options: .init(rawValue: 0))
return imgString
}
Decoding
func ConvertBase64StringToImage (imageBase64String:String) -> UIImage {
let imageData = Data.init(base64Encoded: imageBase64String, options: .init(rawValue: 0))
let image = UIImage(data: imageData!)
return image
}
Note: Tested in xcode 9.4.1
回答6:
Swift 3.0
To convert image to base64 string
Tested in playground
var logo = UIImage(named: "image_logo")
let imageData:Data = UIImagePNGRepresentation(logo)
let base64String = imageData.base64EncodedString()
print(base64String)
回答7:
@implementation UIImage (Extended)
- (NSString *)base64String {
NSData * data = [UIImagePNGRepresentation(self) base64EncodedDataWithOptions:NSDataBase64Encoding64CharacterLineLength];
return [NSString stringWithUTF8String:[data bytes]];
}
@end
回答8:
In swift 2.0 use this extension (credit to Jonas Franz)
extension UIImage{
func toBase64() -> String{
let imageData = UIImagePNGRepresentation(self)!
return imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)
}
}
回答9:
In Swift 3.0 and Xcode 8.0
Encoding :
let userImage:UIImage = UIImage(named: "Your-Image_name")!
let imageData:NSData = UIImagePNGRepresentation(userImage)! as NSData
let dataImage = imageData.base64EncodedString(options: .lineLength64Characters)
Decoding :
let imageData = dataImage
let dataDecode:NSData = NSData(base64Encoded: imageData!, options:.ignoreUnknownCharacters)!
let avatarImage:UIImage = UIImage(data: dataDecode as Data)!
yourImageView.image = avatarImage
回答10:
Swift-Extension:
extension UIImage{
func toBase64() -> String{
var imageData = UIImagePNGRepresentation(self)
return imageData.base64EncodedStringWithOptions(.allZeros)
}
}
回答11:
Swift 4
enum ImageFormat {
case png
case jpeg(CGFloat)
}
extension UIImage {
func base64(format: ImageFormat) -> String? {
var imageData: Data?
switch format {
case .png: imageData = UIImagePNGRepresentation(self)
case .jpeg(let compression): imageData = UIImageJPEGRepresentation(self, compression)
}
return imageData?.base64EncodedString()
}
}
extension String {
func imageFromBase64() -> UIImage? {
guard let data = Data(base64Encoded: self) else { return nil }
return UIImage(data: data)
}
}
回答12:
See my class - AppExtension.swift
// MARK: - UIImage (Base64 Encoding)
public enum ImageFormat {
case PNG
case JPEG(CGFloat)
}
extension UIImage {
public func base64(format: ImageFormat) -> String {
var imageData: NSData
switch format {
case .PNG: imageData = UIImagePNGRepresentation(self)
case .JPEG(let compression): imageData = UIImageJPEGRepresentation(self, compression)
}
return imageData.base64EncodedStringWithOptions(.allZeros)
}
}
回答13:
Swift version - create base64 for image
In my opinion Implicitly Unwrapped Optional in case of UIImagePNGRepresenatation() is not safe, so I recommend to use extension like below:
extension UIImage {
func toBase64() -> String? {
let imageData = UIImagePNGRepresentation(self)
return imageData?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
}
}
回答14:
In Swift 3.0
func decodeBase64(toImage strEncodeData: String) -> UIImage {
let dataDecoded = NSData(base64Encoded: strEncodeData, options: NSData.Base64DecodingOptions.ignoreUnknownCharacters)!
let image = UIImage(data: dataDecoded as Data)
return image!
}
回答15:
I tried all the solutions, none worked for me (using Swift 4), this is the solution that worked for me, if anyone in future faces the same problem.
let temp = base64String.components(separatedBy: ",")
let dataDecoded : Data = Data(base64Encoded: temp[1], options:
.ignoreUnknownCharacters)!
let decodedimage = UIImage(data: dataDecoded)
yourImage.image = decodedimage
回答16:
Swift 4.2 | Xcode 10
extension UIImage {
/// EZSE: Returns base64 string
public var base64: String {
return self.jpegData(compressionQuality: 1.0)!.base64EncodedString()
}
}
回答17:
Swift 5.
class ImageConverter {
func base64ToImage(_ base64String: String) -> UIImage? {
guard let imageData = Data(base64Encoded: base64String) else { return nil }
return UIImage(data: imageData)
}
func imageToBase64(_ image: UIImage) -> String? {
return image.jpegData(compressionQuality: 1)?.base64EncodedString()
}
}
回答18:
For iOS 7+, Objective-C, here's how to make the conversion starting with an image URL:
NSURL *url = [NSURL URLWithString:self.groove.thumbnailURL];
UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
NSString *base64String = [UIImagePNGRepresentation(image)
base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
回答19:
Swift 3.0 and Xcode 8.0
let imageData = UIImageJPEGRepresentation(imageView.image!, 1)
let base64String = (imageData! as Data).base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
print(base64String)
回答20:
Swift 5, Xcode 10.
let imageData = UIImage(named:"imagename").pngData()?.base64EncodedString(options: .lineLength64Characters)
print(imageData)回答21:
//convert Image to Base64 (Encoding)
let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
print(strBase64)
// convert Base64 to Image (Decoding)
let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions(rawValue: 0))!
let decodedimage:UIImage = UIImage(data: dataDecoded)!
print(decodedimage)
yourImageView.image = decodedimage
来源：https://stackoverflow.com/questions/11251340/convert-between-uiimage-and-base64-string